Guestshell is a virtualized Linux-based environment, designed to run custom Linux applications, including Python for automated control and management of Cisco devices. It also includes the automated provisioning (Day zero) of systems. This container shell provides a secure environment, decoupled from the host device, in which users can install scripts or software packages and run them. This module describes and how to enable it. Finding Feature Information, page 1 Information About, page 1 How to Enable, page 5 Configuration Examples for, page 9 Additional References for, page 12 Feature Information for, page 13 Finding Feature Information Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module. Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required. Information About Overview Guestshell is a virtualized Linux-based environment, designed to run custom Linux applications, including Python for automated control and management of Cisco devices. Using, customers can also install, 1
Overview update, and operate third-party Linux applications. It is bundled with the system image and can be installed using the guestshell enable IOS command. The environment is intended for tools, Linux utilities, and manageability rather than networking. shares the kernel with the host (Cisco switches and routers) system. Users can access the Linux shell of and update scripts and software packages in the container rootfs. However, users within the cannot modify the host file system and processes. container is managed using IOx. IOx is Cisco's Application Hosting Infrastructure for Cisco IOS XE devices. IOx enables hosting of applications and services developed by Cisco, partners, and third-party developers in network edge devices, seamlessly across diverse and disparate hardware platforms. This table provides information about the various capabilities and the supported platforms. Table 1: Cisco Capabilities Operating System Supported Platforms Lite (Limited LXC Container) Cisco IOS XE Cisco Catalyst 3650 Series Switches (all models) Cisco Catalyst 3850 Series Switches (all models) (LXC Container) Cisco IOS XE Environment Python 2.7 Custom Python Libraries Montavista CGE7 Supported (Python V2.7.11) Cisco Embedded Event Manager Cisco IOS XE CLIs Ncclient CentOS 7 Supported (Python V2.7.5) Cisco Embedded Event Manager Cisco IOS XE CLIs Supported Rootfs GNU C Compiler RPM Install Architecture Busybox, SSH, and Python PIP install Not supported Not supported MIPS SSH, Yum install, and Python PIP install Not supported Supported x86 Vs Lite The container allows users to run their scripts and apps on the system. The container on Intel x86 platforms will be a Linux container (LXC) with a CentOS 7.0 minimal rootfs. You can install 2
Overview other Python libraries such as, Python Version 3.0 during runtime using the Yum utility in CentOS 7.0. You can also install or update python packages using PIP. The Lite container on MIPS platforms such as, Catalyst 3650 and Catalyst 3850 Series Switches have the Montavista Carrier Grade Edition (CGE) 7.0 rootfs. You can only install or run scripts in Lite. Yum install is not supported on these devices. Security Cisco provides security to ensure that users or apps in the do not compromise the host system. is isolated from the host kernel, and it runs as an unprivileged container. Hardware Requirements for Guestshell This section provides information about the hardware requirements for supported platforms. Table 2: Support on Catalyst Switches Platforms WS-3850-xxx (all) Default DRAM 4 GB Support Supported The minimum system requirement for Catalyst 3850 Series Switches is 4 GB DRAM. Note Virtual-service installed applications and container cannot co-exist. Storage Requirements On Catalyst 3650 and Catalyst 3850 Series Switches, can only be installed on the flash filesystem. Bootflash of Catalyst 3850 Series Switches require 75 MB free disk space for to install successfully. On Cisco 4000 Series Integrated Services Routers, is installed on the Network Interface Module (NIM)-Service Set Identifier (SSD) (hard disk), if available. If the hard disk drive is available, there is no option to select bootflash to install. Cisco 4000 Series Integrated Services Routers require 1100 MB free hard disk (NIM-SSID) space for to install successfully. During installation, if enough hard disk space is not available, an error message is displayed. Bootflash or hard disk space can be used to store additional data by. On Cisco Catalyst 3850 Series Switches, has 18 MB of storage space available and on Cisco 4000 Series Integrated Services Routers, has 800 MB of storage space available. Because accesses the bootflash, it can use the entire space available. 3
IOx Overview Table 3: Resources Available to and Lite Resource CPU Default 1% Note 1% is not standard; 800 CPU units/ total system CPU units. Minimum/Maximum 1/100% Memory 256 MB 256/256 MB Accessing on a Device Network administrators can use IOS commands to manage files and utilities in the. During the installation, SSH access is setup with a key-based authentication. The access to the is restricted to the user with the highest privilege (15) in IOS. This user is granted access into the Linux container as the guestshell Linux user, who is a sudoer, and can perform all root operations. Commands executed through the are executed with the same privilege that a user has when logged into the IOS terminal. At the prompt, you can execute standard Linux commands. Accessing Through the Management Port By default, allows applications to access the management network. Users cannot change the management VRF networking configurations from inside the. Note For platforms without a management port, a VirtualPortGroup can be associated with in the IOS configuration. For more information, see the Sample VirtualPortGroup Configuration section. Stacking with IOx Overview When is installed, a gs_script directory is automatically created in the flash filesystem. This directory is synchronized across stack members. During a switchover, only contents of the gs_script directory are synchronized across all stack members. To preserve data during high availability switchover, place data in this directory. During a high availability switchover, the new active device creates its own installation; the old filesystem is not maintained. The state is maintained during a switchover. IOx is a Cisco-developed end-to-end application framework that provides application hosting capabilities for different application types on Cisco network platforms. The Cisco, a special container deployment, is one such application, that is useful in system deployment/use. 4
How to Enable IOx facilitates the life-cycle management of app and data exchange by providing a set of services that helps developers to package pre-built apps, and host them on a target device. IOx life-cycle management includes distribution, deployment, hosting, starting, stopping (management), and monitoring of apps and data. IOx services also include app distribution and management tools that help users discover and deploy apps to the IOx framework. App hosting provides the following features: Hides network heterogeneity. IOx application programming interfaces (APIs), remotely manage the life cycle of applications hosted on a device. Centralized app life-cycle management. Cloud-based developer experience. How to Enable Managing IOx Before You Begin IOx takes upto two minutes to start. CAF, IOXman, and Libirtd services must be running to enable Guest Shell successfully. Procedure Step 1 Step 2 Command or Action enable Device> enable configure terminal Purpose Enables privileged EXEC mode. Enter your password if prompted. Enters global configuration mode. Step 3 Device# configure terminal iox Configures IOx services. Step 4 Device(config)# iox exit Device(config)# exit Exits global configuration mode and returns to privileged EXEC mode. 5
Managing IOx Step 5 Command or Action show iox-service Purpose Displays the status of the IOx service Step 6 Device# show iox-service show app-hosting list Device# show app-hosting list Displays the list of app-hosting services enabled on the device. What to Do Next The following is sample output from the show iox-service command on an ISR 4000 Series Router: Device# show iox-service Virtual Service Global State and Virtualization Limits: Infrastructure version : 1.7 Total virtual services installed : 0 Total virtual services activated : 0 Machine types supported Machine types disabled : KVM, LXC : none Maximum VCPUs per virtual service : 6 Resource virtualization limits: Name Quota Committed Available -------------------------------------------------------------- system CPU (%) 75 0 75 memory (MB) 10240 0 10240 bootflash (MB) 1000 0 1000 harddisk (MB) 20000 0 18109 volume-group (MB) 190768 0 170288 IOx Infrastructure Summary: --------------------------- IOx service (CAF) : Running IOx service (HA) : Not Running IOx service (IOxman) : Running Libvirtd : Running The following is truncated sample output from the show iox-service command on a Catalyst 3850 Series Switch: Device# show iox-service IOx Infrastructure Summary: --------------------------- IOx service (CAF) : Running IOx service (HA) : Running IOx service (IOxman) : Running Libvirtd : Running The following is sample output from the show app-hosting list command: Device# show app-hosting list App id State ------------------------------------------------------ 6
Managing the guestshell RUNNING Managing the You can start the container in IOS through commands. Before You Begin IOx must be configured and running for access to work. If IOx is not configured, a message to configure IOx is displayed. Removing IOx removes access to the, but the rootfs remains unaffected. Procedure Step 1 Step 2 Command or Action enable Device> enable Purpose Enables privileged EXEC mode. Enter your password if prompted. Enables the service. guestshell enable or guestshell enable [VirtualPortGroup port-number Enables connectivity to the front panel ports. guest-ip ip-address gateway Note The guestshell enable command without gateway-ip netmask netmask any arguments uses the management [name-server ip-address]] virtual routing and forwarding (VRF) instance for networking. Device# guestshell enable Device# guestshell enable VirtualPortGroup 0 guest-ip 192.168.35.2 gateway 192.168.35.1 netmask 255.255.255.0 name-server 10.1.1.1 When using VirtualPortGroups (VPGs) for front panel networking, the VPG must be configured first. The guest IP address and the gateway IP address must be in the same subnet. Front panel ports are not supported Cisco Catalyst 3650 Series Switches, Cisco Catalyst 3850 Series Switches, Cisco Catalyst 9300 Series Switches, and Cisco Catalyst 9500 Series Switches. Step 3 guestshell run linux-executable Device# guestshell run python Executes or runs a Linux program in the. Python Version 2.7.11 is pre-installed on Catalyst 3650 and Catalyst 3850 Series Switches, and Python Version 2.7.5 is pre-installed on ISR 4000 Series Routers. 7
Accessing the Python Interpreter Step 4 Command or Action guestshell run bash Purpose Starts a Bash shell to access the. Step 5 Device# guestshell run bash guestshell disable Disables the service. Step 6 Device# guestshell disable guestshell destroy Deactivates and uninstalls the service. Device# guestshell destroy Enabling and Running the The guestshell enable command installs. This command is also used to reactivate, if it is disabled. When is enabled and the system is reloaded, remains enabled. Note IOx must be configured before the guestshell enable command is used. The guestshell run bash command opens the bash prompt. must already be enabled for this command to work. Note If the following message is displayed on the console, it means that IOx is not enabled; check the output of the show iox-service command to view the status of IOx. The process for the command is not responding or is otherwise unavailable Disabling and Destroying the The guestshell disable command shuts down and disables. When is disabled and the system is reloaded, remains disabled. The guestshell destroy command removes the rootfs from the flash filesystem. All files, data, installed Linux applications and custom Python tools and utilities are deleted, and are not recoverable. Accessing the Python Interpreter Python can be used interactively or Python scripts can be run in the. Use the guestshell run python command to launch the Python interpreter in and open the Python terminal. 8
Configuration Examples for Note The guestshell run command is the IOS equivalent of running Linux executables, and when running a Python script from IOS, specify the absolute path. The following example shows how to specify the absolute path for the command: Guestshell run python /flash/sample_script.py parameter1 parameter2 The following example shows how to enable Python on a Catalyst 3K Series Switch: Device# guestshell run python Python 2.7.11 (default, March 16 2017, 16:50:55) [GCC 4.7.0] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>>>> Configuration Examples for Managing the The following example shows how to enable on a Catalyst 3850 Series Switch: Device> enable Device# guestshell enable Management Interface will be selected if configured Please wait for completion Guestshell enabled successfully Device# guestshell run python Python 2.7.11 (default, Feb 21 2017, 03:39:40) [GCC 5.3.0] on linux2 Type "help", "copyright", "credits" or "license" for more information. Device# guestshell run bash [guestshell@guestshell ~]$ Device# guestshell disable Guestshell disabled successfully Device# guestshell destroy Guestshell destroyed successfully Sample VirtualPortGroup Configuration When using the VirtualPortGroup interface for networking, the VirtualPortGroup interface must have a static IP address configured. The front port interface must be connected to the Internet and Network Address Translation (NAT) must be configured between the VirtualPortGroup and the front panel port. 9
Usage The following is a sample VirtualPortGroup configuration: Device> enable Device# configure terminal Device(config)# interface VirtualPortGroup 0 Device(config-if)# ip address 192.168.35.1 255.255.255.0 Device(config-if)# ip nat inside Device(config-if)# no mop enabled Device(config-if)# no mop sysid Device(config-if)# exit Device(config)# interface GigabitEthernet 0/0/3 Device(config-if)# ip address 10.0.12.19 255.255.0.0 Device(config-if)# ip nat outside Device(config-if)# negotiation auto Device(config-if)# exit Device(config)# ip route 0.0.0.0 0.0.0.0 10.0.0.1 Device(config)# ip route 10.0.0.0 255.0.0.0 10.0.0.1!Port forwarding to use ports for SSH and so on. Device(config)# ip nat inside source static tcp 192.168.35.2 7023 10.0.12.19 7023 extendable Device(config)# ip nat outside source list NAT_ACL interface GigabitEthernet 0/0/3 overload Device(config)# ip access-list standard NAT_ACL Device(config-std-nacl)# permit 192.168.0.0 0.0.255.255 Device(config-std-nacl)# exit Device(config)# exit Device# Usage From the prompt, you can run Linux commands. The following example shows the usage of some Linux commands. [guestshell@guestshell~]$ pwd /home/guestshell [guestshell@guestshell~]$ whoami guestshell [guestshell@guestshell~]$ uname -a Linux guestshell 3.10.101.cge-rt110 #1 SMP Sat Feb 11 00:33:02 PST 2017 mips64 GNU/Linux Catalyst 3650 and Catalyst 3850 Series Switches have a defined set of Linux executables that are provided by BusyBox and Cisco 4000 Series Integrated Services Routers have commands provided by CentOS Linux release 7.1.1503. The following example shows the usage of the dohost command on a Catalyst 3850 Series Switch. [guestshell@guestshell ~]$ dohost "show version" Cisco IOS Software [Everest], Catalyst L3 Switch Software [CAT3K_CAA-UNIVERSALK9-M), Experimental Version 16.5.2017200014[v165_throttle-BLD- BLD_V165_THROTTLE_LATEST_20170531_192849 132] Note The dohost command requires the ip http server command to be configured on the device. 10
Networking Configuration Networking Configuration For networking, the following configurations are required. Configure Domain Name System (DNS) Configure proxy settings Configure YUM or PIP to use proxy settings Sample DNS Configuration for The following is a sample DNS configuration for : [guestshell@guestshell ~]$ cat/etc/resolv.conf nameserver 192.0.2.1 Other Options: [guestshell@guestshell ~]$ cat/etc/resolv.conf domain cisco.com search cisco.com nameserver 192.0.2.1 search cisco.com nameserver 198.51.100.1 nameserver 172.16.0.6 domain cisco.com nameserver 192.0.2.1 nameserver 172.16.0.6 nameserver 192.168.255.254 Configuring Proxy Environment Variables If your network is behind a proxy, configure proxy variables in Linux. If required, add these variables to your environment. The following example shows how to configure your proxy variables: [guestshell@guestshell ~]$cat /bootflash/proxy_vars.sh export http_proxy=http://proxy.example.com:80/ export https_proxy=http://proxy.example.com:80/ export ftp_proxy=http://proxy.example.com:80/ export no_proxy=example.com export HTTP_PROXY=http://proxy.example.com:80/ export HTTPS_PROXY=http://proxy.example.com:80/ export FTP_PROXY=http://proxy.example.com:80/ guestshell ~] source /bootflash/proxy_vars.sh Configuring Yum and PIP for Proxy Settings The following example shows how to use Yum for setting proxy environment variables: cat /etc/yum.conf grep proxy [guestshell@guestshell~]$ cat/bootflash/yum.conf grep proxy 11
Additional References for proxy=http://proxy.example.com:80/ PIP install picks up environment variable used for proxy settings. Use sudo with -E option for PIP installation. If the environment variables are not set, define them explicitly in PIP commands as shown in following example: sudo pip --proxy http://proxy.example.com:80/install requests sudo pip install --trusted-bost pypi.example.com --index-url http://pypi.example.com/simple requests The following example shows how to use PIP install for Python: Sudo -E pip install requests [guestshell@guestshell ~]$ python Python 2.17.11 (default, Feb 3 2017, 19:43:44) [GCC 4.7.0] on linux2 Type "help", "copyright", "credits" or "license" for more information >>>import requests Additional References for Related Documents Related Topic Programmability commands Document Title Cisco Catalyst 3850 Series Switches Command Reference Python module CLI Python Module Zero-Touch Provisioning Zero-Touch Provisioning MIBs MIB MIBs Link To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: http://www.cisco.com/go/mibs 12
Feature Information for Technical Assistance Description The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. Link http://www.cisco.com/support Feature Information for The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature. Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required. Table 4: Feature Information for Feature Name Release Cisco IOS XE Everest 16.5.1a Feature Information is a secure container that is an embedded Linux environment that allows customers to develop and run Linux and custom Python applications for automated control and management of Cisco switches. It also includes the automated provisioning (Day zero) of systems. This container shell provides a secure environment, decoupled from the host device, in which users can install scripts or software packages and run them. In Cisco IOS XE Everest 16.5.1a, this feature was implemented on the following platforms: Cisco Catalyst 3850 Series Switches 13
Feature Information for 14